XY Plot+ for AVEVA PI Vision

PI Vision XY plot with regression and envelopes built in

Plot one measured value against another instead of against time. XY Plot+ adds regression lines with R², reference curves, operating envelopes and a time trail to your PI Vision display. It is a separate Vision Library+ symbol, and it complements the XY Plot that ships with PI Vision.

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Read the XY Plot+ documentation →

XY Plot+ in PI Vision with a scatter plot of one value against another, a regression line and a shaded operating envelope drawn as a closed list of x,y points, next to the reference curve settings
XY Plot+ in PI Vision: a scatter plot with a regression line and an operating envelope, next to its settings. Demo data. Select the image to enlarge.

PI Vision XY plot with regression and reference curves

Show how two values relate, and compare the live points with a fitted line, a reference curve or an operating envelope.

Regression line with equation and R²

Fit a line through the plotted points and read the equation and R² on the chart.

  • Regression on or off for each Y value.
  • A choice of regression model, linear by default.
  • Optional zero intercept, so the line passes through the origin.
  • Equation and R² shown on the chart, with your own color, width and line style.
  • Save the fit as a reference curve.
XY Plot+ with a dashed regression line, its equation and R² on the chart, next to the Analysis settings with regression, model, force zero intercept, show equation and show R²
A regression line with its equation and R², next to the Analysis settings. Demo data. Select the image to enlarge.

Reference curves with above and below coloring

Draw a manufacturer or design curve and see which points sit above or below it.

  • A polynomial curve from its coefficients, or a curve from a list of x,y points.
  • A start and end of the curve on the X axis.
  • Points colored above or below the curve, with your own colors.
  • An optional tolerance band, absolute or in percent.
  • The number of points above and below in the legend.
XY Plot+ with a green reference curve, points colored blue above and yellow below it with counts in the legend, next to the Reference Curves settings with color points by this curve and tolerance
Points colored above and below a reference curve. Demo data. Select the image to enlarge.

Operating envelopes

Draw the area where operation is allowed and see how the live points sit against it.

  • A closed shape from a list of x,y points, one pair per line.
  • The envelope outline in your own color, width and line style.
  • Optional fill with an adjustable opacity.
  • Enter or edit the points in the pane; the chart updates at once.
XY Plot+ Reference Curves settings with the closed list type, a list of x,y points for the envelope, color, width, line style, show, fill and opacity
Envelope settings with a closed list of points. Demo data. Select the image to enlarge.

XY plot pairing and time trail in PI Vision

Decide how the two values are matched up in time, and see where the operating point has been.

Pair an X value with its Y values

Pick which value goes on which axis and how the pairs are formed.

  • Each source is used as X or Y, or as a gate to filter pairs.
  • Each Y is paired with an X, so one X can serve several Y values.
  • Pairing by timestamp, with interpolation to match the samples.
  • Display units for AF attributes.
XY Plot+ data source settings with Use as X, Y or Gate, Pair with, Pairing by timestamp or position, the Interpolated method, and the Appearance and Analysis sections
Data source settings: use as, pair with, pairing and method. Select the image to enlarge.

Time trail

Color points from oldest to newest, so you can see where the process came from and where it is heading.

  • Oldest and newest colors for the points, with both in the legend.
  • Optional lines that connect the points in time order.
  • A number of recent points to highlight.
  • Works best on a short time range, so the trail stays readable.
XY Plot+ with the time trail enabled, points colored from oldest in gray to newest in blue, with the Time Trail settings for oldest and newest colors, connect in time order and recent points
The time trail enabled on one hour of data, next to its settings. Demo data. Select the image to enlarge.

XY plot tooltip, zoom and download

Read exact values and look closer, without leaving the display.

Hover values and toolbar

Hover a point to see both values and when they were measured, and use the toolbar to move around the plot.

  • Tooltip with the Y value, the X value and the time.
  • Toolbar with pan, box zoom, zoom in and out, and reset.
  • A download button in the toolbar.
  • Title, legend, grid, data labels and axis ranges can be set to match your display.
XY Plot+ with the toolbar showing pan, box zoom, zoom in, zoom out, reset and download, and a hover tooltip with the Y value, the X value and the time of a point
The toolbar and a hover tooltip with both values and the time. Demo data. Select the image to enlarge.

PI Vision XY plot examples

Four common ways teams use XY Plot+ on their displays.

Pump or fan against its curve

Data
Flow on X, head or power on Y, from the live sensors
Settings
Reference curve from the manufacturer coefficients, points colored above and below, an optional tolerance band
Shows
Whether the machine runs on its curve

Operating envelope

Data
Two process values that must stay inside an allowed area
Settings
A closed list of x,y points drawn as a shaded area
Shows
Whether the operating point stays inside its envelope

Cause and effect

Data
A setpoint or load on X, a response on Y
Settings
Regression line with its equation and R²
Shows
How strongly one value drives the other

Start-up or transient path

Data
Two values during a start-up, shortened to the period of interest
Settings
Time trail with oldest and newest colors and lines in time order
Shows
Where the process came from and where it is heading

Related symbols: Combo Chart+ for trends over time, Histogram+ for the distribution of one value, and Control Chart+ for stability against control limits.

Watch the PI Vision XY plot in action

An 8-minute walkthrough that builds an XY Plot+ from scratch: pairing, regression, time trail, reference curve, operating envelope, gate and a time window selected with Combo Chart+ rulers.

XY Plot+ product demo (8 min). Demo data.

XY Plot+ FAQ

Questions we are asked most often. Read the XY Plot+ documentation or ask a technical question.

How is XY Plot+ different from the XY Plot in PI Vision?

PI Vision includes its own XY Plot symbol for plotting values against each other. XY Plot+ is a separate Vision Library+ symbol. It adds regression lines with equation and R², reference curves with above and below coloring, operating envelopes, a time trail, a hover tooltip with both values and a toolbar for zooming. Both symbols can be used on the same display.

What can I plot against what?

Numeric PI Points and AF attributes. One value goes on the X axis and one or more values go on the Y axis. Values that are not numeric, and bad values, are left out of the plot.

Do I need to enter the curve or envelope by hand?

Yes. A reference curve is a polynomial from its coefficients or a list of x,y points, and an envelope is a closed list of x,y points. You can also save a fitted regression line as a reference curve.

Does XY Plot+ change anything in the PI System?

No. XY Plot+ only reads data. Zooming and hiding a series change your own view and not the display or the PI System.

What do we need to run it?

PI Vision 2021 or later with PI Web API, and PI AF Server 2018 SP2 or later. XY Plot+ runs in PI Vision and uses each user’s existing PI permissions.

How do we get XY Plot+?

XY Plot+ is part of Vision Library+, together with the other Vision Library+ symbols. Request a trial to test it in your own PI Vision environment.

Try XY Plot+ in your PI Vision

XY Plot+ is included in Vision Library+, the PI Vision custom symbol library from Software Athlete. Test it on your own displays and data.

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Browse all Vision Library+ symbols · XY Plot+ documentation